Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
Open the Prime Video channel, then go to Settings, then Deregister your device. This will remove it from the Amazon account. You might need to uninstall the Prime channel, reboot, then install it again to completely remove the old account.
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